Determine the number of physical CPUs / Core for KVM on Linux

Sometimes you have to plan your vCPUs assignment for KVM guests. so here are a list of definition that I have collected:

When you assign CPUs to KVM, you are actually assigning Virtual Processors, which can be seen by running:
cat /proc/cpuinfo | grep "^processor"

To get the number of cores your physical host supports:
cat /proc/cpuinfo | grep "cpu cores" | uniq

List the number of physical CPU Chips that you have:
cat /proc/cpuinfo | grep "physical id" | sort | uniq | wc -l

Finally you can get all information by running:

Good article on how to optimise KVM